Molecules of Biology

Question 1

Compound

Answer 1

A molecule containing different types of atoms

Question 2

Element

Answer 2

Contains a single atom

Question 3

Organic compounds contain which element?

Answer 3

Carbon, which can form 4 bonds with other atoms. Carbon dioxide is the only inorganic compound containing Carbon.

Question 4

Polymers

Answer 4

Strings of repeated units

Question 5

Monomer

Answer 5

Individual unit of a polymer

Question 6

What is the monomer of a protein?

Answer 6

Amino acid. There are millions of possible proteins, and each have a specific amino acid sequence. Proteins contain carbon, hydrogen, oxygen, and nitrogen.

Question 7

The shape of a protein determines its

Answer 7

Function. If the shape of a protein changes, its function changes or can no longer be carried out.

Question 8

Dehydration Synthesis

Answer 8

Forms peptide bonds. 2 hydrogen and 1 oxygen are removed to form water. In amino acids, connection is formed at rightmost carbon.

Question 9

Hydrolysis

Answer 9

Breaks peptide bonds. Water is added.

Question 10

Amino Acid backbone structure

Answer 10

• NH2 is the amino group
• COOH is the carboxyl group
• The R group is the side chain that gives each amino acid its unique properties.

Question 11

Carbohydrate monomer

Answer 11

Monosaccarides

Question 12

General chemical formula for the carbohydrate

Answer 12

C(n)H(2n)O(n). The molecules have a 1:2:1 ratio, but as bonds form the ratio changes slightly as water is removed.

Question 13

Glucose vs Fructose

Answer 13

Although the formula is the same, the structure is different.

Question 14

Diasaccaride

Answer 14

Carbohydrate made by 2 monomers, like maltose and sucrose.

• Maltose is formed by 2 molecules of glucose by dehydration synthesis. C₁₂H₂₂O₁₁.
• Sucrose is formed when glucose combines with fructose by dehydration synthesis. C₁₂H₂₂O₁₁..

Question 15

Purpose of Carbohydrates

Answer 15

• Quick energy, breaks into glucose, which enters blood.
• Can be converted to fat for storage, or protein to form muscle.

Question 16

Polysaccaride

Answer 16

3 or more monosaccarides bonded together. Examples include glycogen, starch, and cellulose, which differ in the way the glucose are linked together.

• Animals store glucose as glycogen in the liver short term.
• Plants store glucose as starch
• Cellulose is the structural polysaccaride that forms the cell walls of plants.

Question 17

Lipid monomers

Answer 17

Hydrocarbons (CH₂)

Question 18

Hydrophobic

Answer 18

Nonpolar, don’t interact with water.

Question 19

Fatty acids

Answer 19

Long hydrocarbon chains with a carboxyl group (COOH) at one end.

Question 20

Glycerol

Answer 20

An alcohol (-OH) with 3 carbon atoms.

Question 21

3 most common forms of lipids

Answer 21

1. Triglycerides- 3 fatty acids bonded to a glycerol molecule. Most common form in human blood, and how fat is stored.
2. Phospholipids- similar in structure to triglycerides, but one fatty acid chain is replaced with a phosphate group (PO₃). They are hydrophilic on phosphate end, and align their polar and nonpolar ends when they interact.
3. Cholesterol- formed by rings of hydrocarbon. Found in blood tissues and blood of animals, used to maintain cell membranes and produce steroid hormones (testosterone).

Question 22

Saturated lipids

Answer 22

Solid at room temperature, do not contain double bonds.

Question 23

Lipid bilayer

Answer 23

In unsaturated fats, the tail spreads the molecules apart.

Question 24

Steroid hormones

Answer 24

• 4 fused carbon rings
• Hydrophobic

Question 25

Nucleic Acids

Answer 25

• Monomer is a nucleotide
• Found in cell nucleus
• DNA and RNA. DNA goes from DNA to RNA to proteins.

Question 26

Why can’t DNA and RNA nucleotides be exchanged?

Answer 26

DNA uses a different sugar (deoxyribose, no oxygen) than RNA (ribose).

Question 27

A nucelotide is made up of

Answer 27

A sugar, a phosphate, and a nitrogen base.

Question 28

Which chemicals act as nucleotide bases?

Answer 28

• adenine, guanine, cytosine, thymine
• In RNA, thymine is replaced with uracil.
• G matches with C, A matches with T
• GC pairs are stronger, and make a DNA strand with more of these pairs more stable.

Question 29

DNA structure

Answer 29

• A ladder that twists into a double helix
• Sugar and phosphate form the sides, while the bases form rungs.
• Each DNA strand is different due to unqiue order of nucleotides.

Question 30

What is a complementary nucleic acid strand?

Answer 30

Complementary strands form base pairs with each other at each nucleotide.

Question 31

RNA structure

Answer 31

• RNA is single stranded
• It can assume various shapes and form base pairs with itself.

Question 32

What type of bond holds base pairs together?

Answer 32

Hydrogen bond